Electric circuit



(No Model.)

J. 6. WILSON.

ELECTRIC CIRCUIT.

Patented Dec. 17, 1889.

PETERS. prmumumo hv. Washington. :1 c.

UNITED STATES PATENT OFFICE.

JOHN CORNELIUS \VILSON, OF BOSTON, MASSACHUSETTS.

ELECTRIC CIRCUIT.

SPECIFICATION forming part of Letters Patent No. 417,304, dated December 17, 1889.

Application filed July 23, 1889. Serial No. 318,408. (No model.)

To aZZ whom it may concern- Be it known that 1, JOHN CORNELIUS Win soN, of Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in Electric Circuits, of which thefollowing description, in connection with the accompanying drawing, is a specification, like letters on the drawing representing like parts.

This invention has for its object to construct and arrange an electric circuit whereby telephonic communication may be carried on undisturbed by inductive influences from neighboring disturbing wires.

In accordance with this invention two complete circuits or metallic loops are preferably arranged substantially parallel to each other, or in nearer proximity to each other than any disturbing wires. A condenser and telephonic instrument are included or connected in multiple are between the two circuits, a switch being preferably included in said connectingwire, normally opening it. As herein shown, one of the metallic loops is employed as a signaling-circuit, including circuit-changing devices and a battery. In practice the dis turbing or inductive impulses passing over the circuits become neutralized in the condenser, so that their effect is lost.

The drawing shows in diagram a telephonic and signaling circuit embodying this invention.

The circuit a is represented as a metallic circuit including the battery a, circuit-changing devices a and receiving relay a and hence termed the signaling-circuit. The circuit 1) (represented in dotted lines) is shown as a metallic or complete loop extended sub stantially parallel to the circuit a, or in nearer proximity thereto than any disturbing wire is placed.

The condenser c and telephonic instrument c are included between the two circuits to b and wire (1 in multiple are, a switch, as 0 preferably being employed to open said connecting-wire. Any disturbing wire acts to cause momentary and disturbing impulses of like intensity and polarity to traverse the two wires between which the condenser and telephones are connected, and these impulses necessarily act inductively to neutralize and destroy each other in the same manner as if the telephones were connected in a conducting-circuit instead of an inducting one.

As herein shown, three signal-boxes are represented, which contain the circuit-changing devices, telephonic instruments, and condenser, and at the central station a signal-receiving apparatus and telephonic receiving apparatus are included.

The condenser 0, through which the signalilnpulses cannot pass, effectually prevents short-circuiting or the formation of independent metallic loops, while for telephonic purposes such metallic loops are utilized.

Signaling instruments or keys may be i11- cluded in both circuits, if desired, and signaling will not affect telephonic communication.

I claim- 1. Two metallic circuits or loops arranged adjacent to each other, combined With telephonic instruments and a condenser included in multiple are between the said two circuits, substantially as described.

2. Two metallic circuits or loops arranged adjacent to each other, one of which contains circuit-changing devices, a battery, and receiving instruments, combined with telephonic instruments and a condenser included in multiple are between said metallic circuits or loops, substantially as described.

Two independentmetallic circuits, conibined with a cross or connecting wire between said circuits, including telephonic instruments and a condenser, substantially'as described.

In testimony whereof I have signed my n amc to this specification in the presence of two subscribing witnesses.

J OHN CORNELIUS WILSON.

lVitnesses:

GEO. W. GREGORY, B. DEWAR. 

